Picture a triangle with one person at the point and a wide row of people along the bottom. Something starts at the point and travels to the wide part: an order, a plan, a big idea, or just your eyes. Top-down names that direction of travel. The movement begins at the top, and whatever is below receives it.
可以想成一個三角形：尖端只站一個人，底下那一排有很多人。有東西從尖端往下走——可能是命令，可能是計畫，可能是一個大概念，也可能只是你的視線。top-down 可以想成在描述這個方向：從上面出發，下面接收。
登入就可以看每一支怎麼連回核心畫面。